Many children with autism spectrum disorders (ASD) have difficulty learning words, which negatively impacts their functional independence and quality of life. Unfortunately, relatively little is known about the learning mechanisms that underlie these deficits, which has important theoretical and clinical implications. This study will address this gap in knowledge by examining the impact of statistical learning and non-social visual attention on word learning in children with ASD. Implicit eye-gaze methods will be the primary methodology because they capture real-time information about learning and attention. Because of their limited task demands, these methods are appropriate for children with a range of abilities. Many studies have focused exclusively on high-functioning children with ASD, thus limiting research and clinical implications for the broader population. The use of eye-gaze methodology in this study facilitates the inclusion of children with a broad range of language and attentional abilities. Statistical learning (i.e., sensitivity to linguistic regularities) is a roust language-learning mechanism in typical development, but almost nothing is known about statistical learning in autism. Specific Aim 1 (Study 1) investigates a form of statistical learnin known as cross-situational word learning, which supports word learning in ambiguous contexts. Because children with ASD have difficulty using social cues to determine word meanings and thus experience many ambiguous learning situations, it is vital to characterize their cross-situational word-learning abilities. It is hypothesized that the ASD group will have impaired cross-situational learning abilities but that considerable variability will emerge. Specific Aim 2 will characterize this variability by examining two prerequisite skills--the ability to recognize recurring visual stimuli across contexts (Study 2a) and the ability to form a label-object association (Study 2b). A significant relationship between prerequisite skills and cross-situational learning is anticipated in the ASD group. It is well known that children with ASD demonstrate atypical social attention (e.g., joint attention), but many children also demonstrate impairments in non-social visual attention. Specifically, many children with ASD show atypical attentional orienting (e.g., prolonged disengagement of attention) that may impact their ability to use cross-situational learning mechanisms. Specific Aim 3 (Study 3) will investigate the relationship between cross-situational learning and an established, independent visual orienting task. Study 4 will be an exploratory study that examines the relationship between visual orienting during the training phase of the cross-situational learning task (Study 1), and learning outcomes. This study is based on recent work with typically developing infants. Visual orienting, specifically disengagement, is expected to predict cross-situational learning in children with ASD in Studies 3 and 4. Findings from this study will inform theories of ASD and language acquisition, and may have clinical implications for maximizing the effectiveness of existing treatment paradigms and designing new intervention programs to facilitate language acquisition in children with ASD. PUBLIC HEALTH RELEVANCE: The goal of this research is to understand the mechanisms that underlie word-learning deficits in children with autism spectrum disorders (ASD). Specifically, this study will evaluate cross-situational word learning in children with ASD, examine the impact of prerequisite learning skills, and characterize the relationship between non-social attention and cross-situational word learning. This work will inform theories of autism and theories of language acquisition. Study findings may also have implications for maximizing the effectiveness of existing language treatments and designing novel intervention programs for children with ASD.